Archibald bannatyne



(No Model.)

BANNATYNE. BALANCE ESGAPEMENT FOR WATGHES.

' No. 443,248. Patented Deo.'23, 1890..

UNITED STATES PATENT OFFICE,

ARCIIIBALD BANNATYNE, OF \VATERBURY, CONNECTICUT, ASSIGNOR TO THE INATERBURY CLOCK COMPANY, OF SAME PLACE.

BALANCE-ESCAPEMENT FOR WATCHES.

SPECIFICATION forming part of Letters Patent No. 443,248, dated December 23, 1890.

Application filed February 7, 1890. fierial No. 339,552- (No model.)

To all whom it may concern.-

Be it known that I, ARCHIBALD BANNATYNE, of WVaterbury, in the county of New Haven and State of Connecticut, have invented a new Improvement in Escapement Mechanism for Clocks; and I do hereby declare the following, when taken in connection with accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure 1, a detached view in side elevation showing an escapement-lever provided with my improved pallet-pins, an escapementwheel having its teeth suitably shaped to cooperate with the peculiarities of the said pins, and a balance-wheel; Fig. 2, a detached view of the escapeinent-lever in its entirety; Fig. 3, a plan view thereof arranged to show the length of the pallet-pins; Fig. 4, an enlarged view of one of the pins in transverse section.

My invention relates to an improvement in the escapement mechanism of clocks, the object being to simplify and cheapen the same, and to secure a more scientific and free action thereof.

\Vith these ends in view my invention consists in a pallet-pin havinga straight lockingface and a curved impulse-face, in an escapement-lever adapted to have the Pallet-pins driven directly into it and held in place solely by friction, and in certain details of construction and combinations of parts, as will be hereinafter described, and pointed out in the claim.

My improved pallet-pin has a straight locking-face A and a curved impulse-face B in whatever form it may assume. By providing the pin with a straight locking-face it presentsa plane surface to the action of the teeth C of the escapement-wheel D, the outer edges of the teeth, which are undercut, being first and always engaged by the pin, whereby the teeth are virtually held away from the pin and prevented from securing upon it any overhold which must be overcome by a slight reverse movement of the wheel which the same is forced to make in releasing the pin at the expense of power and freedom of action in the train, Whereas with an ordinary palletpin of round cross-section the outer edges of the teeth of the wheel out over, so to speak, the locking-face of the pin, which is thus drawn by the power behind the wheel into the undercut portions of the teeth thereof, and can only be released by a slight reverse action of the wheel at the expense of power and a free action, as above referred to.

As herein shown, my improved pallet-pin is wedge-shaped in cross-section, such form being desirable because it secures enough stiffness in the pin to make it feasible to drive it into place, and also because it gives the pin sufficient surface to be held in place solely by friction when driven. I would have it understood, however, that I do not limit myself to making the pins in this form, it not being essential to have the locking-face of the pin tangential to its impulse-face, as in a pin which is wedge-shaped in cross-section. These pins may be cheaply and well made by drawing them in the required form from Wire, and then cutting the same up into pin lengths. The said teeth of the escapement-wheel, being undercut on one edge, are broader at their ends than at their bases. Their outer ends are beveled so as to present the proper angle of impulse to the pallet-pins for imparting the required motion to the balance-wheel F.

The escapement-lever G, havingan impulsefork at one end and a banking-fork at the other end, is of ordinary construction except for having two cars II II formed integral with it, and projecting laterally in alignment from its opposite sides, respectively. The said ears are each constructed with holes in shape corresponding to the wedge shape of the palletpins. The two pallet-pins are driven into the said holes in the ears, and are retained in place therein solely by friction. The provision of the lever with ears, as described, therefore avoids the additional expense and complication attendant upon the use of the independent carrier mounted upon the verge-shaft, and heretofore employed for carrying the palletpins,which are soldered or screwed into it.

The said balance-wheel F is provided in its completed form with radial rectangular balance projections I. The advantages of this upon each side between said forks, the said ears formed integral with said lever, eo1nbin ed with two pallet-pins, made substantially wedge shape in cross-section, the said ears respectively constructed with holes in shape corresponding to the wedge shape of said pins,

and the said pins foreedinto the said holes in 20 said ears, substantially as described.

ARCHIBALD BANXATYNE.

Nitnesses: H

WM. A. HOLGATE, Ann. C. DEPEW. 

